You'll want to catagorize a range of power outputs that a certain diameter will work with after that you can "push" the limits and tweak a bit by changing angles so which ever blade design you choose you'll want to be able to change the mounting angle to make the generic blade work for diferent alts with different quirks(ie, hard starting or high cut-in etc.).
There will likely be those who disagree but I would speculate a reasonable generic style would be something like a 24-4415 at the root and a 00 to 2412 at the tip and about 12 degrees of twist root to tip with an adjustable mounting angle allowing for about 5 degrees minimum to 8 or so for slower machines. There are better/fancier profiles but a generic blade will likely be best suited to a basic profile that works well over a wide range of conditions. Although I don't believe this is the best for the individual alt. I can see a purpose for a good generic blade for those who don't want or lack the means to build there own.
I guess you could look at this as an attempt to provide a generic profile that is scalable over a range of diameters(unfortunately a small range) as there is no generic diameter. I would also think it's entirely possible some may chose to run a 3 or 5 blade configuration to manipulate a generic design. I won't speculate on cord width/taper as I have a somewhat different philosophy on this. I will say though I'm of the opinion the smaller the diameter the wider the cord as a % of blade length at each station.
Any seconds?
